Hayes' Dominion brakes are already a feature-rich four-pot brake and Hayes has sought to reduce the system weight with its new Dominion T4. The result is a claimed 100g saving with a pair of brakes which would make them lighter than comparable brakes like SRAM's Codes and even Shimano's XTR four-pot brakes.
Hayes says this weight saving was achieved through a 'meticulous effort to eliminate excess material' whilst keeping the core design and functionality unchanged. The biggest changes are made around the lever, which is now made out of carbon by Hayes' sister company Reynolds. The weight savings didn't stop there, with internal hardware like bolts, push rods, compression fittings and banjo fittings now being made from Titanium – hence the new 'T' moniker.
While much of the lever body couldn't be changed, Hayes refined the design shaving off as much excess material as possible. The result is a brake that weighs a claimed 276g per wheel.
You still get Hayes' Stable Rate Linkage and sealed bearings which offer a lighter lever feel to help give precise braking modulation. The caliper also still features two adjustment grub bolts to help with caliper alignment and simplifying setup.
Despite what the spec sheet says, it appears one feature to have been sacrificed in the progress of lightness is the tool-less reach adjustment. Gone is the lever-mounted thumb dial, replaced with a small grub screw instead.
Adding carbon fiber and titanium increases the costs and the Dominion T4 brakes are priced at $325 per wheel, and the aluminum-backed T4 pads are $38.99 USD.